Can abdominal muscles be tightened laparoscopically? For those who don't need fat or skin removed down there?

General surgeons have tried what you describe and I’m sure you can find someone willing to do it especially if you’re paying for it.
Results are meager because the muscle fascia is on the outside of the muscle layer and correct muscle tightening requires a re-draping the skin/fat layer in order for it not to accumulate in the midline.
Typically procedures that work well become industry standard and this has not.
There’s a reason patients do not opt for this procedure.
I nobody wants to have a full tummy tuck but it is the correct way to treat pregnancy related skin laxity and or muscle separation.
Choose surgeons based on who delivers the most natural looking belly buttons with a low set scar that follows anatomic contours naturally.
Best,
Mats Hagstrom MD

Hi and welcome to our forum!
Laxity of the abdominal wall may be due to the effects of pregnancy or significant weight fluctuation. It is usually accompanied with lax abdominal skin and soft tissue, requiring abdominoplasty. Laparoscopic rectus muscle plication (and mesh placement if necessary) can be performed if it is the sole cause of abdominal fullness.
Visit a board certified plastic surgeon for evaluation and discussion.
Best wishes...